Bicycle.



Patented Sept. 26` 1899.

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BICYCLE. Appnmim med .mue zo, 189e.)

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c UNITED STATES PATENT OFFICE- GEORGE DAVIES, AOF SEATTLE, WASHINGTON.

BICYCLE.

SPECIFICATION forming part of Letters Patent No. 633,814, dated September 26, 1.899. Application filed J'nne 20,1899. Serial No. 721,233. iNo model.)

To all whom it may concern:

Be it known that I, GEORGE DAVIES, a citizen of the United States, and a resident of Seattle, county of Kin g, State of Washington, have invented certain newr and useful lmprovements in Bicycles, of which the following is a specification, reference being had therein to the accompanying drawings, in Which-u Figure l is a side elevation of a'bicycle, showing the improvement. Fig. 2 is a detail plan View of the rear portion of the bicycle. Fig. 3 is a detail View, and Fig. et is a'detail section taken on the line 4 4 of Fig. 3.

The object of this invention is to provide a simple device by means of which an easier foot movement may be secured than is possible with the crank mechanism now in use without increasing the length of the cranks or materially increasingl the foot movement required to rotate them. f

Referring to the various parts by numerals, l designates the crank-arms of, an ordinary crank-operated bicycle, to the outer ends of each of which on pivot 2 is mounted a substantially horizontal lever 3, to the shorter forward arm of which latter is secured the usual pedal 4, the rear longer arml of this lever carrying at its extreme end a roller 5, this roller being grooved and confined Within a continuous guide or track 6, suitably fastened to the side of the bicycle-frame near the rear hub. The two cam tracks or guides are coincident with each other, and each cam has its upper and lower portions formed on a circle struck from its center, the front and rear sides of the guide being bulged or extended, respectively, forward and rearwardin a substantially V-shaped form, giving the guide or raceway somewhat of an oval shape, the longer diameter running horizontally of the cam and being in substantially the same horizontal plane as the drive-shaft. One of the inclined parts of each of the angular or V-shaped por-Y tions of the cam is pivoted, as at 8, and adapted to yield inward as` the roller 5 passes over it, this pivoted part or gate being normally pressed outward into the path of the roller by means of a spring 8. The free end of each pivoted part terminates at the apex ofthe angular or V-shaped portion of the guide.

As the bicycle is driven in the usual man- 'ness and ease of the foot movement.

ner by rotating the pedals the crank-arms describe a true circle and the roller 5 travels around the cam groove or track 6, the pedals moving in the substantially oval-shaped orbit (shown in dotted lines in Fig. 3) which is eccentric to and forward of the center of the crank-shaft. l As the roller 5 passes over each of the gates the gate is forced inward, and just as the roller reaches the apex of theangular portion the gate automatically springsV out- Ward, so that its end forms an abutment or guide to direct the roller into the adjacent angular portion, whereby theroller will be caused to travel continuouslyin one direction around the cam-track. The radius of the circular portion of the cam-guides being but slightly shorter than the radius of the crank the lever 3 will be maintained in a substantially horizontal position, whereby the diameter of the orbitof the pedal will be but slightly longer than the diameter of the circle described by the crankarm. It will be observedthat my device overcomes the deadcenters and materially contributes to steadi- On the upstroke of the pedal the crank and the forward part of the horizontal lever will overla p, and the leverage Will thereby be reduced to normal.

It will be observed that the increase in le verage is obtained just Where it is desirednamely, upon the doWnstroke-the leverage beginning to increase just as the pedal passes over the center and continuing to increase to a point horizontally inline with the driveshaft and then gradually decreasing toward the lower limit of the stroke.

As will be observed, Ashorter crank-arms may be employed than are now in use, and the loss of leverage that would thusordinarily follow will be compensated for by the in- A creased leverage obtained by my device,there by making it possible to propel high-geared bicycles with less effort and a comparatively shorter foot movement.

The roller 5 is preferably grooved for better guidance around the track, the track bea ing formed by the edges of the guide-frame, and a portion of the outer frame or track is omitted at 9, so that the roller may be in serted in the guideway and removed therei from.

IOO

I elaim- A l. In combination, a crank-driven bicycle, a substantially horizontal lever att-ached t-o each crank, a pedal on the forward end of each lever and a roller on the rear end of each lever, a continuous guide-frame secured to the frame on cach side and receiving and guiding the rollers on the respective levers, said guideframe having its front portion extended forward and its rear portion extended rearward into angularor V-shaped projections or bnlges, and adeviee at each angular part of the guide to automatically prevent the return of the roller as it passes over the center at front and back, whereby the rollers Will move continuously around in the guide in the same direction as the cranks and pedals.

2. In combination with a crank-driven bicycle, a substantially horizontal lever pivoted to each crank and carrying a pedal at the for- 1 ward end and a roller at its rear end, continuous guides adapted to receive the rollers on the levers, one guide being affixed to either side of the frame, and said guides each having a forward angular extension at its center, a pivoted gate upon the upper side of said angular part said gate being normally pressed outward into the path of the roller, whereby the roller will be compelled to pass continuously around the guide and prevented from reversing its direction at the forward end of its stroke.

In testimony whereof I hereunto affix my signature, in the presence of two witnesses, this 22d day of May, 1899.

GEORGE DAVIES.

Witnesses:

F. M. MULDooN, FRANK A. PoNTIUs. 

